The present invention generally relates to magnetic recording and apparatuses for recording and reproducing signals on and from a recording medium by means of rotary recording and reproducing heads, and more particularly to a drum assembly for use in such a magnetic recording and reproducing apparatus for carrying the rotary recording and reproducing heads.
Magnetic recording and reproducing apparatuses such as video tape recorders (VTR) and digital audio tape recorders with rotary recording and reproducing heads (R-DAT) record and reproduce signals such as video signals, digital audio signals and the like on and from a recording medium such as a magnetic tape by means of two or four rotary magnetic heads mounted on a rotary body. In such a magnetic recording and reproducing apparatus, recording signals and reproduced signals are transmitted between the rotary recording and reproducing head and a recording and reproducing circuit disposed in a main body of the magnetic recording and reproducing apparatus through a rotary transformer locating at an interface between the rotary body and a stationary drum fixed to the main body of the magnetic recording and reproducing apparatus. The stationary drum supports the rotary body in a rotative manner and comprises an electrical means electrically connected the recording and reproducing circuit. Conventionally, a same number of rotary transformers as to the number of the rotary recording and reproducing heads are used, and a rotary recording and reproducing head corresponds to a rotary transformer in one to one correspondence. Thus, each rotary recording and reproducing head is connected to a corresponding rotary transformer within the rotary body.
Generally, video tape recorders capable of performing various reproducing functions such as a still picture reproducing, slow motion reproducing and the like use a greater number, for example, five, six or more of rotary recording and reproducing heads. It is also noted that so called 8 mm VTR cameras and R-DAT apparatuses use rotary body which diameters are considerably smaller as compared to the video tape recorders of the usual VHS or beta systems. Thus, there is a problem that a space for mounting a rotary transformer in such a rotary body is limited and that the number of the rotary transformers to be mounted in a rotary body is reduced.
A reproduced signal from the rotary recording and reproducing head is usually faint and easily interfered by external noises as the signal is transmitted from the rotary recording and reproducing head to the recording and reproducing circuit of the magnetic recording and reproducing apparatus through the rotary transformer. Thus, there is a problem that a signal to noise ratio of the reproduced signal is easily deteriorated.